The Bronsted plot for hydrolysis of diphenyldiazomethane by
carboxylic acids is smooth but curved, approaching an asymptotic
limit below 10 mo1-1 dm3 s-1• Regardless of the details of the theory
used, such a limit requires that the transition state is approached
via a state (or virtual state) substantially (- 70 kJ mol-1) above the
starting state in free energy, but still having an intact bond from
H+ to its original conjugate base. Such a state has been called a
reaction complex,6 and is thought to be analogous to the intimate
ion pair of solvolysis reactions
